| 摘要 |
Apparatus for measuring the speed of rotation of a wheel or the angular orientation thereof relative to a fixed point. A first portion of a transmitter unit is positioned along the periphery of the wheel and a second portion of the transmitter unit is positioned at a stationary location outside of the wheel. The two portions of the transmitter unit together from one or more lined screens which, when one is viewed through the other, create a moire interference pattern. Optical means are provided to read the interference pattern created as the wheel is moved to thereby determine the speed or angular orientation thereof. |
